SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4ca6e6323362387e478cae543ed5512dc96ff14f10276f869b7fa9835e095cb' 
  AND token = 'jTnEY1lKJphXVRscBHF4Eb6y7m79aQIy9bf/vZwqVQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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