SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fec9814ce1bb61a5ae099d6ecbe0efdf9665a9a8f5e063ef76a4043c5fafe98' 
  AND token = '5w0+rL5BEfxFRXanIcCXjmOPZFaGGHijBi7dbpxsMqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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