SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0b39b55afdb090e83e0a9d17c5920b6aba45014f7a4266f0cf5b2aa83679f24' 
  AND token = 'BmaLCxYvwRNnn5Mt1aKGwVFVWQ5cgGubgpgysdzfQ24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}