SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dad896ddbf284eebdddf561a2727bffe4135df49e29ee4746547d4c450da20f' 
  AND token = 'Fxrfk8S7RjWI5gEdfmICcFOuJVUNon8lOlpplCNmK/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}