SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b398bdceb19cc954939c11b09169fb2cacd0b04ccf1b8b0224f055e60e295ff' 
  AND token = '+TAiOxoRrpQzOieW2mRHHRi7mW9A4GBFMKEeNtEvICM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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