SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbbd760d868df7bbfa60374128cb376eb7a2e38151dd419c389db41ba5485d0e' 
  AND token = 'QmwCTOaw/Ic+/5eBlQBxU307dZRtgr+ka0QuCSRKkak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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