SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46d2693a5e9c9cf4ec5f6530b4f99901af8588f7cb05fbc83e385418d423d953' 
  AND token = 'u/VSSdAJtUPnN5s/w6uitgmPQcIjQ7wbN62zNjETPuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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