SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b82d1d76317cbed8d5ed4c28b4961a434508671f5e06685dbb227dcd8ae8b85' 
  AND token = 'oPW6ZHwjFlLwo7900Feuz75WZO2/ThcH3/BR2GhQTzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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