SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd2b857d2ee3435c04afc9bc9b826f13d00eec667a78cb5164e5cbcb01112a54' 
  AND token = 'M7WRzOGBRoVXzevoMiZkcsm1TyMwhCEZjJ3rRxXBFnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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