SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c95e4138f989f94c8564dcdaffb4ab92e677c975c222846991df2d0e87a5a753' 
  AND token = 'iFIhNZVad3+GzjY3Q6BnOpeshK0yDEWFQKc5qWTEtDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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