SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d89e7b90a4b63ff0a675c2b3105345c2e1f15e26d962ea60ac51e21266bc658' 
  AND token = 'e7vpItK65T46GynR/6Qbp9LqP2iMOcCNSQrYTLf/TVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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