SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '711929a874f43ff1a73de0f2eccd1f15480eb20d331eb098f94286e5e07d7a74' 
  AND token = 'wX0X6HVJvUyq5ma3xGdvG+pfDX8xAWPzo3CkPXfsn+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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