SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df64fe30c55a8a4d1adc4a801b820e644efc0b44fe20dcefe13f97067723c47d' 
  AND token = 'hGejYgPaiTv35YYvtyWvHy5lhqYx7g+MW32u7FARgCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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