SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc19cb9f6523d569b022e12ab2600c6a7105e08379bde6566e1c8f179a1d29fc' 
  AND token = 'RQQZJoRMh3z5kUAuOHEds0IITu6KbMvLPwYKhxge5Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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