SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa84783f03e370814b41a9541dc138ba289fa6ff19eb03cbb0c1d050c40b8677' 
  AND token = 'ROK+rhR+jBESBXr7I1hnNCb8w2KGIxDRdjP+/7pchag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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