SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8ded241cfba4a1b409869eab710c761b30c747d9d79cdda4d511fe944e8faea' 
  AND token = 'Wc9cINBFu14enyFTr3zipbP6ygmoBFRMv4B5ivqMHpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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