SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76f8c7ccaea578fcc4263bf76f26c08d7e6432c47d99022003c07694088d02bc' 
  AND token = 'odDwjxE/1NsbVBvdkiqbAqb5hxXZqlKxBfCTzx1wgYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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