SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5120401838114199442eaef688054ab6611298502c25f7af6409d5032dcc07f7' 
  AND token = 'G7Pfu3DmYNXXxUIWUJ6EqzQW42kW216WGh0mO2Zz9Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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