SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2457e1b1a5d313bde2e4ed9d9f6b78387a456ffb4eb9a07bf3810660007a960c' 
  AND token = 'dRLpSToGVfRbVBmODJY0o2c9QaboyWfx2u+dfuus6DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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