SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72cb751369e40a78a845bd7f4dcc7d130549d7cb32451cfd8bd99cb3345cc57e' 
  AND token = 't7lQFVMgxZEjb1Ynf8NDu08smqs30IJF3rDdSmGTS0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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