SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '305c06b50d6699b14eafbac9b437fbb48696c091811c78fda588aaf937575a9e' 
  AND token = 'zhzBqTxFjQnaar9+j2Dw5YZerwhaFNcUAAITdLWP3UE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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