SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fa235c59b95dba67915ee1905dd99c95c823a36e43c58634ffc609f46c51a3a' 
  AND token = 'kb/IJHE4cjKKMILzyhc07g8fVx15w5XGgNJ8CZTTI48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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