SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc1cc805dcbe01c1d0d5c09e5bfaced815198b91fbddcdc556ce2e7e3a1664d1' 
  AND token = 'n3pcCAIr2m3T/yIOwoM7g8doDTg6Y+FhO2z/S5JpUx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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