SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6c6ac3954451a0067a375799d12f4b80a186b8df018746d1453584ab2602152' 
  AND token = 'JSwoCEdqjj3/zDzO7BLBHTdKII0X2+ww+l6ui5xYdXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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