SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '073859372eecccbbddee8ea539ab5251524828b1cffd47af42d2da18669a5ab1' 
  AND token = 'cAjbzszX005/IB14MuFJbBJWjq/5Ci+QKIjPqcxRODg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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