SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd34158e92ecc608584bbff3cf623a031548c3903ca4d75bf7da1f23d0459ba24' 
  AND token = 'JVYu0atjMEGWhUL4R8EzFEi98RG69q/J1t+1gqr7iz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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