SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785b01b21afa23426e1873ada94e24f301e1b26630d7d83945925b2d3669752b' 
  AND token = 'Wg8w3VgnTTjLhBf85CyprQC0Jt4PKW7U4V4TzLfyMJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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