SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1b78e4352468b9b3c2c39a3e3f970d508392df3570b79630bd97400a6c4bf0d' 
  AND token = 'n2gXVVidHph10zlXej4YGoDru8r6CPZa+Uh4iNmzwwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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