SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d6237f8b0f2c77efd4ff393f451101498e51044b3d77e194403540461ff991' 
  AND token = 'ZPtUzh5T4tcth44zHKzYxKSE/gBydKdPUFNJoPyOWKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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