SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99e5864b2d985124806cc63e09aad694fb6e6fef63adf6a5913945306b891872' 
  AND token = '59hKtcBiWPJ5mIUeZya4/RJ1P2LTtCSIgrERhmkI8Ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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