SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8bc9fd0db15fc2eba49a9ea8253bcd6d3bea71afad659286b7a2aa7534f5d45' 
  AND token = 'NznsbQ4O/ixSgGJMN9EAJj8SiHD2NnRQP47pXa6s3YA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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