SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bebe07307f95f2c3460cf2a39a2ca46f88a3db1127d07053d292e423e16c711' 
  AND token = 'gWzQGmeLEIutZS/+Kf39BLjhEm58DSao4Fx6yUCTzA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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