SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f5c206524d08c4f871951aed263ea4515bd215b31ecfdba89d47991f8243ff0' 
  AND token = 'piFHajZeU/W3/AMPbdbQgop3lX4bTsWIyBGRIcuErIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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