SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ada280ed6cde7335ecfc5fa33fdb949b8f108d590cfbdd6ee21978f0d8523f31' 
  AND token = 'oPSFVsKEHO/nbnxvugcwX+MmlP40+TCZFMFDzmlAqWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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