SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c502e633ed3185a08f6a58bd4aebd532cf92c06652627b4073973a0bec58405' 
  AND token = 'SLemm9sZaX11l5K3MzzCutA5A2YKE+dMGztQzTkaPSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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