SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '85d4cf07b05aa716665f553cedcc6498297df758baea5a769dd222390482a249' 
  AND token = 'UJ9yjmDTCnkr8CTjNrKVh/jqA4dGPw0L3/2qykYPdWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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