SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95af4703b61aecad5fd27d2c9746e5743a3f346572b22c64c8ba23eedde29b17' 
  AND token = 'A7ASOR49qpHdb3qlSLIQI8ykp2xUsjWMmn2FIIFzgog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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