SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eafd83b0baa87a40cc8eb1f6193549e24e93d5d206c1e23099d8e05920bca74' 
  AND token = 'Jj6dakgf0ewSUG2JXuC2CKFKoS03UhysOoulGfGofEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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