SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ba692d63402fa25ba3c37a6069ef8acbcc9a433989d8220457cc28fe0d0b795' 
  AND token = 'aICKdVfpDgYd9ck3j3tMJN2PFc21r61uClktUB2fixo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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