SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82153cdb13f56ede4195c307f2a0b01dd9f03e10107258a8939e13f6584f1419' 
  AND token = '1cMMFZjSe8x8IvuJrFTApsIxWaFBREwjhoTAFVHg7Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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