SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb99dab363508372e6c5be61ee0464933568125a3bbcb34f756e724e67c39312' 
  AND token = 'AhJ/E+4yCTkJ1qGcDp62uUzLGgf4XpoPQvoiQvlyD5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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