SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1a612e982f7050cc353d83e6343eb7b5f5f66f0574f9be2ff38cac00be11bb2' 
  AND token = '0bx5sJfglMJrZZ7Wfa+Surp01zidrVRaoBYX5tpGAw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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