SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fbbdca24fcfca3648207a2f8d7cf6696f373ef492f5de9e1caaa79ab9c43778' 
  AND token = 'SM9Yd4JSNq1CfIIEy2fKeMw48zR+NJ626l9LxwZ94lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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