SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eea726f4dda6b6cd80e10fc5171b0738078c852f3ad989e8ebe8eeb448b72696' 
  AND token = 'TRbSYfM6fA79U9hnmo1UoI9il+b014qcEYV9tFRqkN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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