SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4853e9e90713678d05771f50cab22f10ba56437bc2c2ca5d91c6115be9dc6696' 
  AND token = 'Uk18JzAT84y7eCDWCqH1Fi+c16T+oPVula9CAly70g0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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