SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5afbf3c68444c8dc919cd1e1a4d393469adda8bfa8e4caa1facfdf4c75681a4f' 
  AND token = 'TfuTuhPhJdDQus0hvgvldJRbzYtQBQ68AKnB+VM9Ob8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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