SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3551146873866e3e29a4bffc40e3b84bcfc7a9f777f0faa40da62a803b4d97ec' 
  AND token = 'JnO0eGCRKl9s8tBP4lIJB0NEzdH35VJiBRFYJhQefps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}