SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '95c547770b1eb37174fd1feff7354bcd41cea9929a5296e923bb03bd874b3fe3' 
  AND token = '4sxGJjO4NfffNvwcDIWG6pYQgSEiH3wcqqRRchE+Vv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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