SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc6fa9922accfbb01e9f140df0b1f4904d94caba2f4b9d097d4ebc01672eca70' 
  AND token = 'RaveEaQXfiv+2VGf6iZBKEAqbDQegA5DGrCm+d1iWiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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