SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d4f9df039353892c6193fd46894caa9cd54b2291ea2e7c399dc78e81227b74' 
  AND token = 'D1ObBLoAh3PIHZ23Dq0ILPzI1sHWYZnLsJo4lON9pSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}