SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '642fe0a5bb844e54f7973ba5cf922cb29c0d1578e0b8df26d66cc7e57f11b3e6' 
  AND token = 'INMp16DcFizGCjGm1IrcSP7qd3dn7ONi37qEIgAt1po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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