SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0fd48a59780780cf5eca1893ae3aea8d2332d12b5ff1443d7e63e3cf7cbbedf' 
  AND token = 'IwluPvPzR/b/bDQprouWtlVIfAKLUV3aY2L/BexKDRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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