SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8f8410069d73321d7594a7f154a839760177719b4630ec7a197b281a5e9cb5' 
  AND token = 'TWcPLh+YX6IK6zZTQPi22v1wDKH+A43yjlCmgd1OKAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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