SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb1de4c74483e1419b67b7043bc67539fbbb374dafe52027a1f25fa7abb0e79d' 
  AND token = '5W16x/V5ev0RILdus23zIoyWGKNgdfSWf3emUzHAMPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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