SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b606925c0e2a45e8e648ba03c549eb078008aae1f2e20af523bcd02fe248ba8' 
  AND token = 'EWNxFBwjap0kmLqwaJ+Nbss+sKmD6GM4vRwsQfexKaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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