SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0a4a018476bdaa7c8c83fced76a0da06ddd13e42c5f8566a498a4cc8ba5377a' 
  AND token = 'Qf9TKGRFiramvrpR5+2DvCxJCMEJvaNEolGPsKW/cCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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