SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e27a5eaf48c3ee30f5df140ffb61e22665b1388ebe6d548a71eb1d2302470c55' 
  AND token = 'P4HQUHSNKQV/IrwnCGvEqueL3QGrhv9OBAejtBs5DOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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