SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edadb0da9dd0bad4fcc0884f9127a0bb9b423238b7818f41b74e33e181b743e6' 
  AND token = 'OXc+tDRDtvVWk/vMiQTBRQ3XiC9fADnnOIUfKEnkRsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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