SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96e4c41a377125b39214f7aba6ad89fc99820ac398e0e2b6b09081414f55bf51' 
  AND token = 'T6eqMnacK/3lPpib1Gg5wRhMz6huIEiKNOPE0cV6Xfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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