SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac94ca31dbf112c2f57d85360f407dcd2475f37c443376045c738d10d2b05237' 
  AND token = '3OkARKM4jfdBpDNNXhq8lhS+IgmQs/W1W3NHXK+Lxdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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